Self-starting synchronous motor



Feb. 13, 1934. J u l,947,423

SBLF STARTING SYNCHRONOUS MOTOR Filed Jan. 7, 1932 v I ;Mutu James ji aa] Patented Feb. i3, 1934 V l,947,423

UNITED STATES PATENT OFFICE 1,947.423 SELF-STARTING SYNCHRONOUS MOTOR James M. Naul, Fanwood, N. J., assignor to Diehl Manufacturing' Company, Elizabeth, N. J., a corporation of New Jersey Application January 7, 1932. Serial No. 585 ,245 1 Claim. (Cl. 172-1279) This invention relates to synohronous motors ing poles 6 of the field Core 4. The starting poles more particularly of the slow speed type, suitable 6 are energized by the starting coils 20 which are for use in driving phonograph turntables, synin series with each other and, together, are in chronous clocks, etc., and has for an object to multiple with the main exciting coils 10, as indil provide a motor of this type which is self-startcated in Fig. 4 in which L, L represent the a ter- 80 ing and whichpossesses a good running torque. nating Current supply mains and Sw indicates a with the above and other objects in view, as' sin -p s n e-thro swi ch f r s ar i the will hereinafter appear, the invention Comprises otor. the devices, combinations, and arrangements of Inasmuch as the st tin cols 20 e ch se up io parts hereinafter set forth and illustrated in the a Short pa ocal fie d ac oss t e ai gap 18 and 65 accompanying di'awing of a preferred embodiacross the space between the end of each pole 6 ment of the invention, from which the several n t e co respo i f ce 19 of the arm 15, the features of the invention and the advantages atrelative p y Of the p s 6 o O another tained thereby will be readily understood by those to the main p s s u p rt nt. A skilled in the art shading coil 21 is applied to each pole 6 to hold 70 Pig, 1 of th drawing i a plan vi w of a syn the corresponding face '19 of the arm in contact chronous motor embodying the invention. Fig. With the p end Without Chattering. A Sp 2 is a section o the l 2 2 Fig 1 Fig 3 is 22 is applied to the arm 15 to return it to contact a section on the li e 3 3, Fig 1, d Fig 4 is a relation with the stop 23 when the switch Sw is diagram of connections. v opened. 75

The m t r inu t t d is constructed t a It will be understood that, when the switch Sw skeleton cup-shaped frame 1 to the Vertical legs S Closed, the Starting p s 6 Will attract the 2 of which is secured by screws 3 t stack 4 arm 15 with sufhcient forceto overcome the lookof field-laminations having the main poles 5 and ing torque between the teeth Of the main p s 5 starting poles 6. i and the rotor 9. The arm 15 will be quickly 80 Journaled in the central Vertical bearing 7 in drawn intO COhtaCt With the p s 6 and the frame 1 is t motor--shaft 8 Carrying the 9 will be given a sudden starting impulse at or laminated rotor 9. The faces of the poles 5 and Sufficiently near s chronous speed to insuredts the cylindricalface of the rotor 9 are provided continued running ILSte With the main filterwith the usual registering teeth to give the motor nating magnetic field The WhdihgS 10 and 20 85 'synchronous running Characteristics. The poles are referably s designed n proportioned s 5 r energized by the usua] excmng Winding Or to provide a relatively low magnetic density across field coils 10 which are connected in series to the the air D between the main poles and the motor supp1y-circuit L, while such a motor rotor 9 and a relatively high magnetic density in will run synchronously, it is not self-starting. the local magnetic Circuits involving'the Start' 90 According t the present improvement there ing poles 6 and the ends of the clutch-arm 15.

is mounted to turn upon and relative to the motor Havmg thus Set fOrth the nature Of the shaft 8, a one-way Or overruning clutch corn- Ventiomwhatlclaim hereinisi prising a collar 11 having therewithin the eccen- The combination With an altemating current tric cavities 12 for the clutch-rolls 13 backed by Synchronus motor including a stator-core ring 9 the clutch-roll-springs 14 This type of Over having main internal polar projectionsan inrunning clutch is well known, per se; the clutchternal starting P a projection, a shaft, and a collar 11 acting to grip and turn the shaft 8 when toothed rOtOr embraced by the main Polar D turned in a clockwise direction, Fig. 1, while the jeCtiOnSn Of means for Starting Such mOtOT shaft 8 is free to continue running in a clockwise Cluding an Ovemnning clutch connected to the 1 direction after the starting motion of the clutchmotor-Shaw and a clutch-arm Within the range n is stopped, of attraction of said internal start ng polar pro- Screwed to the clutch-collar 11 is the diametrijectmn' cal ann 15 of magnetic material. The arm 15 is JAMES NAUL- formed at its opposite ends with downturned extenslons 16 between which and the inner cylindrlcal surfaces 17 of the field core 4 there are narrow air-:apa 18. The ends of the arm 15 are also formed with the face-portions 19 which are with- 55 .m the range of magnetic attractlon Otthe start- 1 

